The core body temperature is the operating temperature of an organism in deep structures of the body such as the liver, in contrast to temperatures of peripheral tissues such as the organism's skin. The core body temperature of a warm-blooded animal such as a human is usually a strong indicator of the state of the animal's health. For example, the condition of a high temperature is often caused by an infectious disease, and similarly, a high temperature may also indicate that the animal is suffering from a heat stroke. Such conditions, if not treated properly and quickly, may lead to more serious medical conditions and can result in a fatality.
While it is known that the core body temperature of a human tends to have the lowest value in the second half of the sleep cycle and that a human's body temperature typically changes by about 0.5 degrees Celsius (0.9 degrees Fahrenheit) between its highest and lowest points each day, it is important to monitor frequently any significant trends in the individual's core body temperature, such as to assess whether a particular medical treatment is working sufficiently quickly and favorably.
Typically, there have been four methods of trying to obtain the core body temperature of a warm-blooded animal such as a human. First, an oral thermometer may be placed in the mouth. Temperatures taken by this method, however, may be influenced by drinking, eating, or breathing. A second method is to take the temperature of the animal's underarm. Unfortunately, the temperature of the underarm may be vastly different from the core body temperature because the thermometer is placed next to the skin, which is a tool the body uses to control core body temperature. Moreover, skin temperatures are often influenced by factors such as medication, clothing, and external temperature. A third method has been the use of rectal thermometers. Such thermometers are not conveniently administered, often pose psychological discomfort, and present a contamination risk. The fourth method is the use of ear thermometers that measure the temperature of the tympanic membrane a/k/a the ear drum. Such ear thermometers typically involve detecting infrared radiation emitted from the ear drum.
Infrared thermometry is based upon the principle that all material emits electromagnetic radiation as so-called “blackbody” radiation. The emission spectrum, that is, the intensity of the radiation at each wavelength in a continuum of wavelengths, is in accord with Plank's law. For materials at about 60 degrees F. to 100 degrees F., their emission spectra tend to peak in the mid-infrared range, at wavelengths around 10 microns. The intensity of emission is proportional to temperature, and therefore, the temperature of a material can be determined by measuring its infrared emission. Such infrared radiation can be detected by any one of a number of different types of sensors such as thermopiles, pyroelectric sensors, and other types of infrared sensors.
An infrared ear thermometer can be used quickly and easily in a hospital or at home, is not embarrassing to use, and avoids contamination from re-use. Nevertheless, various factors can significantly affect the accuracy of temperature readings obtained by detecting infrared radiation emitted from the ear drum. For example, temperature readings can be affected by a relatively cold outer ear or ear canal, a hairy ear canal, or the presence of possible disease or infection. Moreover, due to variations in physical attributes of ear canal geometry or a defective positioning technique, the temperature readings may be skewed.
The present invention helps insure that the infrared radiation probe inserted into the ear canal is pushed deep enough into the ear canal so as to minimize the effects of the outer ear and ear canal temperature, to minimize the affect of physical contours of and hair within the ear canal, and to direct the probe toward the ear drum, without contacting the ear drum.